One of my favorite sociology experiments happened in 1967, and was completely accidental. During the filming of The Planet of the Apes, actors ate lunch in make-up and costume. It didn’t take long for everyone to notice something odd. Actors unconsciously divided themselves by “species.” Gorillas ate with gorillas; chimpanzees ate with chimpanzees, and so forth. Nor was it an isolated instance. Actors also noticed it on the set of Beneath the Planet of the Apes, and it may have happened while filming the other movies as well. We seem to be hardwired to want to belong to a group, and will seek out others of our “tribe.” It was perhaps best summed up by a college-bound high school senior who, after meeting others with the same major on a university campus, summed it up with “They’re my people.”

I was struck by this modern tribalism yesterday when I dropped by the blog of an author who began their post with a political diatribe which pretty well summed up how the post was going to go. Sure enough, it did, and it wasn’t surprising the regulars were in complete agreement. But why shouldn’t they? This was their “tribe.” Drop by most blogs where the author allows comments (the only reason I don’t is I can’t spare time to play moderator), and you’ll see the same pattern. You’ll get some naysayers, usually outsiders, but most regulars will be in complete agreement. It’s their tribe.

There’s some good things about tribalism. In the tribe you know others have your back. In the real-world “tribes” of actual family and friends, you know that your tribe will be there for you during personal disasters, just as you will be there for them. There’s as much comfort in the tribe now as there was around the camp fire as the wind blew off the glacier and the wolves howled in the night. Yet tribalism has a dark side as well, which we may see in others but seldom our own: We rarely question tribal wisdom.

Part of it comes from the idea that in the tribe you support each other. Another is respect for the “tribal elders.” A great deal of it, though, is that our modern virtual tribes are self-grouped according to interests and beliefs. As such, we’re quick to accept, without question, things that reinforce those beliefs. Someone in the tribe makes a statement and it’s accepted without question as long as it agrees with the beliefs of the tribe.

You can see this every day, from reaction to events in the news to Internet forums to the Blogosphere to informal bull sessions. There will be all sort of comments, save one of the most important: How do we know this to be so?

It can be risky to question tribal wisdom. Once I blundered across the line and was challenged by the “elder,” and in a mildly bullying manner. Except bullying only works if you let it, and after a few curt exchanges I found the “ice field” better company than the virtual tribe, and struck out. I don’t even know if the “elder” realized it was bullying. One of the first reactions to questioning tribal wisdom is to bring the tribesman in-line. Then it ramps up to where the tribesman is booted out (shunned or banned), or leave the tribe on your own.

This can work because of the same reason actors in like costume sat together at lunch while filming the original Planet of the Apes films. People are hardwired to seek out a group, and when they consider themselves a part of one, losing that can be more intimidating than we might admit.

What’s ironic is this particular tribe had pointed at bullying behavior in another tribe. Ah, but it’s much easier for us to see the faults of others when we’re doing much the same thing without a second thought. Which is probably another good reason not to have comments here.

That’s not the darkest thing about tribalism wisdom. No, it’s that you can be surrounded by others of like views to the point that you never even think to question tribal wisdom. Some consider this a modern phenomenon, but it’s as old as humanity itself. If you ever wonder how conspiracy theorists maintain their views, consider that it’s a form of tribalism. Then ask if you have similar blind spots.

If you do question the wisdom of your virtual tribe and find the reaction a bit painful, it’s not so bad out on the ice field. Remember two important things. One is that there’s more people than you out on the ice field. The other is that like people tend to group together. People will always form tribes, virtual or otherwise. It’s what we do. Just be aware of the blind spot of tribal wisdom. And always ask how we know a thing to be so.